Method for preventing overload condition in a circuit switched arrangement

A method carried out in an arrangement that includes a resource provider, and N collections, each collection i including a set of resource users Ti and a set of resources SORi that includes one or more serially-connected shared overloadable resources SORij, interposed between resource users Ti and said resource provider, j being an index that identifies a particular shared overloadable resource in set SORi, and where each call that is established between a resource user in set Ti and said resource provider occupies an overloadable resource element, SORij (q) in each resource j in set SORi, where q=1, 2, . . . or Qj, and Qj is a number corresponding to number of shared overloadable resource elements in resource j, said method being carried out in response to an attempt by a resource user in set Tk to establish a communication connection with said resource provider, comprising the steps of:

• (a) selecting a value of index j in SORkj that was not previously selected;
• (b) when number of unoccupied ones of said resource elements or Qj falls below a first threshold, K1j, affirmatively concluding that said attempt, if it will be processed, will be processed subject to termination of an existing connection;
• (c) when said number is not below said first threshold, K1j, returning to said step of selecting, for another iteration that selects a value of said index j that was not previously selected, unless no such index remains;
• (d) when said number falls at or below a second threshold, K2j, or fails a predetermined availability test, affirmatively declining to process said attempt, and terminating the method;
• (e) when said number does not fall below said second threshold and also passes said predetermined availability test, returning to said step of selecting, for another iteration that selects a value of said index j that was not previously selected, unless no such index remains;
• (f) when no index j that was not previously selected remains, and step (b), in any of said iterations, reached said affirmative conclusion, executing a process for terminating an existing call;
• and
• (g) when no index j that was not previously selected remains, and step (b), has reached said affirmative conclusion in none of said iterations, processing said attempt to establish communication connection with said resource provider for said resource user in set Tk.

A method for managing capacity of a link having a plurality of channels, comprising the steps of:

• when a user desires to establish a connection that will occupy one of said channels for exchange of information with a desired destination, providing to said user a channel for communicating information regarding said destination;
• when number of unoccupied channels among said plurality of channels is above threshold K1, establishing a connection for said user A through one of said unoccupied channels to said destination;
• and
• when said number of unoccupied channels among said plurality of channels is at or below said threshold K1, executing an algorithm that decides whether to drop a call or to not drop a call, based on a probability measure that begins at zero number of unoccupied channels among said plurality of channels is at K1, and monotonically increases to 1 when number of unoccupied channels among said plurality of channels reaches K2, where K1 and K2 are integers, and K2<K1.